Comparison of the present approach with literature reported method for pyranopyrazole synthesis.
| Entry | Catalyst (mol%) | Solvent | Time (h/min) | Temp. (°C) | Yield (%) | TOF | Ref. |
|---|---|---|---|---|---|---|---|
| 1 | Urea (10) | EtOH : H2O | 8 h | r.t | 86 | 1.075 | 68 |
| 2 | Isonicotinic acid (10) | SF | 10 min | 89 | 90 | 56.25 | 69 |
| 3 | Et3N (10) | EtOH | 15 min | Reflux | 65 | 26 | 70 |
| 4 | l-Proline (10) | H2O | 10 min | Reflux | 90 | 56.25 | 71 |
| 5 | γ-Alumina (30) | H2O | 50 min | Reflux | 80 | 3.19 | 72 |
| 6 | β-Cyclodextrin (10) | EtOH : H2O | 15 min | 80 | 92 | 36.8 | 73 |
| 7 | Piperidine (5) | H2O | 10 min | r.t | 83 | 66.4 | 74 |
| 8 | HDBAC (30) | EtOH | 45 min | Reflux | 73 | 3.24 | 75 |
| 9 | B(OH)3 (10) | SF | 10 min | 70 | 85 | 53.12 | 76 |
| 10 | Fe 3 O 4 @NFC@Co( ii ) (0.9) | H 2 O | 15 min | 50 | 98 | 435.5 | This work |